72 



ON THE NON.PERMEABILITY OF GLASS BY 

 WATER. 



No. 1. 



No. 4. 



The following experiments were made in the North and South 

 Atlantic and Indian oceans, by Mr. Rudder, late of Birmingham, 

 during his passage to New South Wales, with the view of ascer- 

 taining whether water passed through the pores of glass bottles, 

 sunk at different depths in the ocean. The result of the experi- 

 ment with the bottle. No. 4, prepared after the manner described 

 in the annexed diagram, and sunk 150 fathoms, clearly proves the 



No.l. 

 E, Piece of wood supporting 

 the cork H at A, and resting 

 against the inside of the bot- 

 tle at B — H, cork. — G, saw- 

 dust and pitch — I, wine — J, 

 canvass passing up the neck of 

 the bottle to the outside, and 

 covered with boiling pitch. — 

 C, wooden plug, driven in with 

 melted pitch upon the body J. 

 — D, iron nail passed through 

 the plug, C, over which a piece 

 of canvass was passed, and that 

 with the canvass at J, pitched 

 over and firmly secured to the 

 neck of the bottle with string, 

 likewise pitched over, as at F. 



No. 4. 

 1, Piece of wood supporting 

 the cork, 4, at 2, and resting 

 upon the bottom of the bottle 

 at 3 — 5, layer of melted pitch. 

 6, cork driven in with melted 

 pitch, and afterwards covered 

 over with a thick layer of pitch. 

 7, cap of sheet lead, driven upon the top of the cork and pitch, 6J and bound 

 down with copper wire and string at 8 — 9, outside coating of pitch, extend- 

 ing from the rim of the lead, covering over the neck of the bottle. 



non-permeability of glass, — a fact which is corroborated by a series 

 of experiments subsequently made by Mr. Wickenden, and describ- 

 ed, by that gentleman, in a very lucid manner, on reading the Paper 

 —of which the following is an abstract — ^before the members of the 

 Birmingham Philosophical Institution. 



A wine-bottle was prepared as described in the annexed diagram. 

 No. 1 ; another was likewise thus secured : — a piece of wood was 



